webclient/js/Messaging.js

import error as popError from GUI.Screen;

var wsLocation = window.location.origin.replace(/^http/, 'ws') + '/play/';
var ws;
var debug = getParameters().debug;
var doLog = debug != undefined && debug.match(/^(?:1|t(?:rue)?|v(?:rai)?)$/i);
var on = false;
var s = 1000; /* ms */
var keepAlivePeriod = 20;
var reconnectDelay = 1;
var routes = {callbacks: [], children: {}};
var messagesQueue = [];
var wsHandlers = {
	open: [function() {on = true; reconnectDelay = 1}, catchUp, ping],
	close: [function() {on = false;}, reconnect]
};

init();

return {
	addEventListener: addEventListener,
	isOn: isOn,
	send: send
};

function get(obj, path, write) {
	write = write || false;
	if(path.length < 1) {
		return obj;
	} else {
		if(obj.children[path[0]] == undefined && write) {
			obj.children[path[0]] = {callbacks: [], children: {}};
		}
		if(obj.children[path[0]] != undefined) {
			return get(obj.children[path[0]], path.slice(1), write);
		} else {
			return null;
		}
	}
}

function getParameters() {
	var o = {};
	window.location.search.substr(1).split('&').forEach(function(s) {
		var t = s.split('=');
		o[t[0]] = t[1];
	});
	return o;
}

function addEventListener(path, callback) {
	if(Array.isArray(path)) {
		var route = get(routes, path, true);
		route.callbacks.push(callback);
	} else {
		if(wsHandlers[path] != undefined) {
			wsHandlers[path].push(callback);
		} else {
			log('Unsupported websocket event "' + path + '"');
		}
	}
}

function messageListener(event) {
	var o = JSON.parse(event.data);
	var path = [];
	var tmp = o;
	while(tmp != undefined && tmp.tag != undefined) {
		path.push(tmp.tag);
		tmp = tmp.message;
	}
	var route = get(routes, path);
	if(route != undefined && route.callbacks != undefined) {
		route.callbacks.forEach(function(f) {f(o);});
	} else {
		console.log("No route found for " + event.data);
	}
	o.direction = 'client < server';
	log(o);
};

function send(o) {
	if(isOn()) {
		ws.send(JSON.stringify(o));
		o.direction = 'client > server';
		log(o);
	} else {
		messagesQueue.push(o);
	}
}

function catchUp() {
	var messages = messagesQueue;
	messagesQueue = [];
	messages.forEach(send);
}

function log(message) {
	if(doLog) {
		console.log(message);
	}
}

function init() {
	connect();
	addEventListener(["Pong"], ping);
	addEventListener(["Error"], function(o) {popError(o.error);});
}

function connect() {
	ws = new WebSocket(window.location.origin.replace(/^http/, 'ws') + '/play/');
	ws.addEventListener('message', messageListener);
	ws.addEventListener('open', function(e) {
		wsHandlers.open.forEach(function(handler) {handler(e);});
	});
	ws.addEventListener('close', function(e) {
		wsHandlers.close.forEach(function(handler) {handler(e);});
	});
}

function reconnect() {
	setTimeout(connect, reconnectDelay * s);
	if(reconnectDelay < 16) {
		reconnectDelay *= 2;
	}
}

function isOn() {
	return on;
}

function ping() {
	setTimeout(function() {
		if(isOn()) {
			send({tag: "Ping"});
		}
	}, keepAlivePeriod * s);
}